witness

Attestation of a fact or event; testimony.

She can bear witness, since she was there at the time.

May we, with the warrant of womanhood and the witness of a good conscience, pursue him with any further revenge?

One who sees or has personal knowledge of something.

As a witness to the event, I can confirm that he really said that.

[…]thyself art witness— I am betrothed.

Someone called to give evidence in a court.

The witness for the prosecution did not seem very credible.

From the evidence of witnesses and of the recorded passing times, including the time at which the circuit breakers were tripped when the wires were brought down, the train was travelling at a speed of not less than 70 m.p.h.

One who is called upon to witness an event or action, such as a wedding or the signing of a document.

The bridesmaid and best man at a wedding typically serve as the witnesses.

Something that serves as evidence; a sign or token.

Laban said to Jacob, […] This heap be witness, and this pillar be witness.

To furnish proof of, to show.

This certificate witnesses his presence on that day.

round he throws his baleful eyes / That witness'd huge affliction and dismay

To take as evidence.

Depression often goes undetected until it is too late . Witness the recent White House suicide.

To see or gain knowledge of through experience.

He witnessed the accident.

This is but a faint sketch of the incalculable calamities and horrors we must expect, should we be so unfortunate as ever to witness the triumph of modern infidelity

To present personal religious testimony; to preach at (someone) or on behalf of.

Instead, Niebuhr's God was the God witnessed to in the Hebrew Scriptures and the New Testament, the Bible of the Christian world.

To see the execution of (a legal instrument), and subscribe it for the purpose of establishing its authenticity.

to witness a bond or a deed

A Jehovah's Witness.